import turtle

def draw_chessboard(size):
    turtle.speed(0)
    turtle.pencolor("black")
    turtle.penup()
    turtle.goto(-size/2, size/2)
    turtle.pendown()

    # Draw horizontal lines
    for _ in range(9):
        turtle.forward(size)
        turtle.penup()
        turtle.backward(size)
        turtle.right(90)
        turtle.forward(size/8)
        turtle.left(90)
        turtle.pendown()

    turtle.penup()
    turtle.goto(-size/2, size/2)
    turtle.left(90)

    # Draw vertical lines
    for _ in range(9):
        turtle.forward(size)
        turtle.penup()
        turtle.backward(size)
        turtle.right(90)
        turtle.forward(size/8)
        turtle.left(90)
        turtle.pendown()

turtle.setup(800, 800)
draw_chessboard(400)
turtle.done()